The present invention relates generally to electrochemical devices, and more specifically, to a method and article using thin electrolyte coatings on a ceramic support structure. More specifically, the present invention relates to a method of forming a near net shape ceramic support structure and depositing a thin electrolyte layer on one surface of the ceramic support structure. Even more A specifically, the present invention relates to a ceramic support structure having a plurality of thin tubular walls in which the electrolyte layer is in the range of approximately 10xcexc-100 xcexcm.
The ceramic oxygen generators disclosed in U.S. Pat. Nos. 5,871,624 and 5,985,113, which are hereby incorporated by reference in their entirety into the instant specification, overcame many of the limitations inherent in previous approaches for electrochemical devices utilizing an oxygen-conducting electrolyte. The integral base described in U.S. Pat. No. 5,871,624 provided a simplified, low resistance method for electrical interconnection between individual electrochemical elements. The base 14 also enables the formation of a hermetic chamber, separating the atmospheres at the anodic and cathodic surfaces from each other, for a large number of individual elements with a single seal joining like materials. The disclosed arrangement, unlike planar stack configurations, has shown the ability to withstand internal pressures greater than 1200 psi at room temperature and to generate oxygen at over 45 psi outlet pressure. Such pressures are necessary for integration of ceramic oxygen generator systems (COGS) with pulse dosing and anesthesia devices for medical applications.
U.S. Pat. Nos. 5,871,624 and 5,985,113 disclose that the ceramic element also acted as the electrolyte. The support structure includes a base portion (also called a tube support portion in the ""113 patent) and a plurality of tubes. The electrical efficiency of the design was limited by the thickness of the tubular walls of the ceramic element that could be formed by existing technologies such as powder injection molding.
An object of the present invention is to improve the electrical efficiency of an electrochemical apparatus by forming thin electrolyte and electrode films onto a support structure.
Another object of the present invention is to provide a tubular region of the support structure which is electrically conductive and permeable to oxygen-containing gasses.
Another object of the present invention is to provide a planar (manifold) region of the support structure which is not electrically conductive nor permeable to oxygen-containing gasses.
Still another object of the present invention is to provide a method of manufacturing a thin film electrochemical apparatus.
Yet another object of the present invention is to reduce the wall thickness of the electrolyte portion of the ceramic element.
Still another object of the present invention is to form an electrochemical apparatus without vias.
These and other objects of the present invention are achieved by a method of manufacturing a thin film electrochemical apparatus. A near net shape ceramic element is molded including a planar base region and a plurality of tubular regions. The planar base region is infiltrated with a non-conductive material. Each of the tubular regions is infiltrated with a porous conductive material. A porous catalytic electrode material is applied onto the infiltrated regions to form one of a cathodic and anodic surface. A ceramic electrolyte coating is deposited onto the porous catalytic electrode material. A porous catalytic electrode material is applied onto the deposited ceramic electrolyte coating. A porous conductive material is deposited onto the porous catalytic electrode to form the other of the cathodic and anodic surface.
The foregoing and other objects of the present invention are achieved by a method of manufacturing a thin film electrochemical apparatus. A near net shape ceramic element is molded including a base region and a plurality of tubular regions. A portion of each of the base regions is masked to form a first base region and a second base region. A porous conductive material is deposited onto the plurality of tubular regions and the first and the second base regions. A porous catalytic electrode material is first applied onto the deposited porous conductive material to form one of a cathodic and anodic surface. A dense ceramic electrolyte is deposited onto the applied catalytic electrode material. A porous catalytic electrode material is deposited onto the deposited ceramic electrolyte to form the other one of the cathodic and anodic surface, and depositing a porous conductive material onto the porous catalytic electrode to electrically connect the second applied catalytic electrode over the first base region to the porous conductive material on the second base region.
The foregoing and other objects of the invention are achieved by a thin film electrochemical apparatus, including a ceramic support structure including a planar base region and a plurality of tubular regions. An electrically conductive region is formed in each said plurality of tubular regions. The planar region is electrically non-conductive and provides a hermetic barrier. A first catalytic electrode layer is formed on a surface of each of the tubular regions. An electrolytic layer is adjacent to the first catalytic electrode layer. A second catalytic electrode layer is adjacent to the electrolytic layer.
Still other objects and advantages of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein the preferred embodiments of the invention are shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description thereof are to be regarded as illustrative in nature, and not as restrictive.